JP5853937B2 - Optical transmission line card - Google Patents

Description

  The present invention relates to an optical transmission line card mounted on a chassis type switch.

  The chassis type switch is configured by mounting a plurality of optical transmission line cards on a chassis.

  Optical transmission line cards are equipped with components that generate heat, such as optical elements such as ITLA (tunable wavelength laser assembly) and APD (avalanche photodiode), LSIs that perform communication processing, etc., and it is necessary to cool these heat generating components. There is. In particular, when ITLA (including mini-ITLA) is used as the light source, the luminous efficiency decreases as the element temperature rises. Therefore, control for increasing the drive current is automatically performed to obtain a constant light intensity. There is a case where a vicious cycle occurs in which a larger amount of heat is generated. In order to prevent such a problem from occurring, it is necessary to sufficiently cool the heat generating component.

  Usually, the chassis is provided with a cooling fan, and outside air is taken into the chassis by the cooling fan to cool the heat generating components of the optical transmission line card. The front panel of the optical transmission line card is provided with an air hole for sucking outside air into the chassis or exhausting cooled air out of the chassis.

  2. Description of the Related Art Conventionally, in order to efficiently cool a heat generating component with outside air supplied by a cooling fan, a heat radiating plate and a heat radiating fin are attached to the heat generating component.

  In addition, there exists patent document 1 as prior art document information relevant to invention of this application.

JP 2010-2111157 A

  In recent years, in order to be able to mount optical transmission line cards at a higher density, there has been a demand for smaller and thinner optical transmission line cards.

  As a result, in the optical transmission line card, there is a case in which the mounting of components on the board is increased in density, so that a space for passing cooling air cannot be secured and the heat generating components cannot be sufficiently cooled.

  In addition, if optical transmission line cards are mounted in the chassis at high density, the capacity of the cooling fan (flow rate of cooling air) per optical transmission line card cannot be secured sufficiently, and there are sufficient heating parts. In some cases, it may not be possible to cool down.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical transmission line card that can sufficiently cool a heat-generating component even when it is reduced in size and thickness.

  The present invention was devised to achieve the above object, and a front panel provided integrally with a substrate is exposed from a chassis and mounted on a chassis type switch, and outside air is sucked into the chassis by the front panel. In the optical transmission line card in which air holes for exhausting the air in the chassis are formed, the optical transmission line card is provided in thermal contact with the heat-generating component mounted on the substrate, and is thermally applied to the front panel. A heat transfer plate that transfers heat from the heat-generating component to the front panel, and the outside air sucked in the air holes or the air discharged to the air holes, An optical transmission line card configured to pass between a heat transfer plate.

  The heat generating component may be fixed to the surface of the heat transfer plate on the substrate side, the heat transfer plate may be fixed to the substrate through a spacer, and the heat generating component may be provided to be separated from the substrate. Good.

  The heat generating component may be a wavelength tunable laser assembly.

  A plurality of heat generating components may be provided in thermal contact with the heat transfer plate.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a case where it reduces in size and thickness, the optical transmission line card which can fully cool a heat-emitting component can be provided.

1 is a perspective view of an optical transmission line card according to an embodiment of the present invention. It is a perspective view of the optical transmission line card of the comparative example used as the comparison object of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a perspective view of an optical transmission line card according to the present embodiment.

  As shown in FIG. 1, the optical transmission line card 1 has a substantially rectangular substrate 2. Although not shown, the optical transmission line card 1 is mounted on a chassis type switch by inserting both side portions 3 of the board 2 into rails provided in the chassis and sliding the board 2 into the chassis. It is what is done.

  On the substrate 2, an ITLA (wavelength variable laser assembly) 4a, an LN (lithium niobate) modulator 4b, and an APD (not shown) are mounted as optical components 4. These optical components 4 are connected by an optical fiber 5. The ITLA 4a and the LN modulator 4b are mounted on the front surface S of the substrate 2, and the APD is mounted on the back surface R of the substrate 2.

  An electrical connector 7 that is connected to the backplane when the board 2 is inserted into the chassis is provided at an end part (an end part on the left back side in FIG. 1, hereinafter referred to as a tip part) 13 of the board 2 in the insertion direction. ing.

  In addition, an optical fiber 5 is optically connected to the optical component 4 at an end portion (an end portion on the right-hand side in FIG. A front panel 9 having a connector 8 is integrally provided (including a case where the front panel 9 is fixed to the board 2 with screws). In the optical transmission line card 1, the front panel 9 is also provided with an optical transceiver insertion portion 10 for inserting an optical transceiver for near field communication.

  The optical transmission line card 1 is mounted on the chassis type switch with the front panel 9 exposed from the chassis. The front panel 9 is made of metal, and has an air hole 9a for sucking outside air into the chassis or exhausting air inside the chassis. Although not shown, a cooling fan is provided in the chassis into which the optical transmission line card 1 is inserted. With this cooling fan, outside air is sucked from the air holes 9a or air inside the chassis is exhausted. It is like that.

  Further, a plate-like protrusion 9b that extends forward in the insertion direction in parallel with the substrate 2 is provided at the upper end of the front panel 9, and an optical transmission is provided on the surface of the protrusion 9b opposite to the substrate 2. When the line card 1 is mounted on the chassis type switch, a gasket 6 is provided to block the gap between the chassis and the electromagnetic wave leakage.

  On the surface S of the substrate 2 is mounted an LSI 11 for processing optical signals and controlling each optical component 4. On the LSI 11, a heat dissipating member 12 that dissipates heat generated in the LSI 11 is provided.

  Now, the optical transmission line card 1 according to the present embodiment is provided in thermal close contact with the heat generating component 15 mounted on the substrate 2 and is also provided in thermal close contact with the front panel 9. 15 is provided with a heat transfer plate 16 for transferring heat from the front panel 9 to the front panel 9, and external air sucked in the air holes 9 a or air discharged to the air holes 9 a is interposed between the substrate 2 and the heat transfer plate 16. It is configured to pass through.

  Examples of the heat generating component 15 in the optical transmission line card 1 include ITLA 4a, APD, and LSI 11. In the present embodiment, the heat transfer plate 16 is configured to transfer the heat generated in the ITLA 4a to the front panel 9. Since the front panel 9 is exposed from the chassis, the heat generated by the ITLA 4a is radiated to the outside of the chassis via the heat transfer plate 16 and the front panel 9.

  As the heat transfer plate 16, it is desirable to use a plate made of a material having high thermal conductivity. For example, a plate made of aluminum can be used.

  In the present embodiment, the ITLA 4a which is the heat generating component 15 is directly fixed to the surface of the heat transfer plate 16 on the substrate 2 side, and the heat transfer plate 16 is fixed to the substrate 2 via the spacer 16a. The ITLA 4a is provided so as to be separated from the substrate 2. As a result, heat from the ITLA 4a can be efficiently transferred to the heat transfer plate 16, and a space through the cooling air is ensured between the substrate 2 and the flow of cooling air is improved. In addition, it is possible to efficiently dissipate heat to the cooling air.

  The heat transfer plate 16 extends from the mounting position of the ITLA 4a to the front panel 9, and is fixed to the protruding portion 9b of the front panel 9 by screws or the like. With such a configuration, a space is formed between the substrate 2 and the heat transfer plate 16, and this space is cooled with air (external air sucked through the air holes 9a or air discharged into the air holes 9a). ) Will flow.

  The cooling air flowing between the substrate 2 and the heat transfer plate 16 cools the heat-generating component 15 such as the ITLA 4a and the LSI 11, and simultaneously cools the heat transfer plate 16. That is, the heat transfer plate 16 not only plays a role of transferring heat from the heat generating component 15 (here, ITLA 4a) to the front panel 9, but also serves as a heat release plate that radiates heat directly from the heat transfer plate 16 to the cooling air. Also plays. In FIG. 1, the heat transfer plate 16 is drawn in a plate shape, but the heat transfer efficiency can be increased by forming irregularities on the surface of the heat transfer plate 16 to increase the surface area, or by providing heat dissipation fins integrally. Can be further improved.

  In the present embodiment, a notch 17 is formed at the end (side end) of the heat transfer plate 16 on the front panel 9 side. This notch 17 is used to assemble the optical transmission line card 1. Sometimes it is intended to make it easier to attach the connector 8 to the front panel 9.

  As described above, in the optical transmission line card 1 according to this embodiment, the heat transmission component 15 mounted on the substrate 2 is provided in thermal contact with the front panel 9 and is provided in thermal contact with the front panel 9. The heat transfer plate 15 includes a heat transfer plate 16 that transfers heat from the heat generating component 15 to the front panel 9, and the outside air sucked in the air holes 9 a or the air discharged to the air holes 9 a is supplied to the substrate 2 and the heat transfer plate 16. It is configured to pass between.

  With this configuration, heat generated in the heat generating component 15 can be radiated from the front panel 9 to the outside, and directly from the heat transfer plate 16 to the cooling air. The generated heat can be efficiently radiated.

  As a result, it is possible to efficiently cool the heat generating component 15 even when the components are mounted on the board 2 with high density due to miniaturization and thinning, or even when the capacity of the cooling fan is insufficient. . That is, according to the present invention, the optical transmission line card 1 can be further reduced in size and thickness, and a chassis type switch in which the optical transmission line card 1 is mounted at a higher density can be realized.

  For comparison with the optical transmission line card 1 according to the present embodiment, a comparative optical transmission line card 21 as shown in FIG. 2 was manufactured, and the temperature of the ITLA 4a was compared. The optical transmission line card 21 has basically the same configuration as the optical transmission line card 1, and is provided with a heat radiating plate 22 that is not connected to the front panel 9 in place of the heat transfer plate 16.

  When the temperature of the ITLA 4a during the operation of both the optical transmission line cards 1 and 21 is compared, the temperature of the ITLA 4a is compared with the optical transmission line card 21 of the comparative example in the optical transmission line card 1 according to the present embodiment. It was possible to reduce the temperature by about 4 ° C., and it was confirmed that the heat generated in the ITLA 4a can be efficiently radiated by the present invention.

  The present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

  For example, in the above embodiment, the case where the LSI 11 is provided with the heat radiating member 12 formed separately from the heat transfer plate 16, but the heat transfer plate 16 and the heat radiating member 12 may be integrally formed. Good. That is, a plurality of heat generating components 15 (in this case, ITLA 4a and LSI 11) may be provided on the heat transfer plate 16 so as to be in thermal contact therewith. As a result, the number of parts can be reduced and the cost can be reduced.

1 Optical Transmission Line Card 2 Substrate 4 Optical Component 4a ITLA (Wavelength Tunable Laser Assembly)
4b LN modulator 9 Front panel 9a Air hole 15 Heating component 16 Heat transfer plate 16a Spacer

Claims (4)

A front panel provided integrally with the board is exposed from the chassis and mounted on the chassis type switch, and an air hole is formed in the front panel for sucking outside air into the chassis or exhausting air inside the chassis. Optical transmission line card
Together provided thermally closely to provided et the heat-generating component on the substrate, the thermally closely provided on the front panel, transfer heat heat transfer heat from the heat generating component on the front panel Plate for
An optical transmission line card configured to pass outside air sucked through the air holes or air exhausted into the air holes between the substrate and the heat transfer plate. The heat generating component is fixed to the surface of the heat transfer plate on the substrate side, the heat transfer plate is fixed to the substrate through a spacer, and the heat generating component is provided so as to be separated from the substrate. Item 5. The optical transmission line card according to Item 1. The optical transmission line card according to claim 2, wherein the heat generating component is a wavelength tunable laser assembly. The optical transmission line card according to claim 1, wherein a plurality of heat generating components are provided on the heat transfer plate so as to be in thermal contact therewith.